This is a digital stop watch with start, stop and reset options. This embedded project is developed using Arduino-Uno with online 3D modeling program Tinkercad.

pinMode(pin, mode) - Configures the specified pin to either input or output.

• pin: the Arduino pin number to set the mode of.
• mode: INPUT, OUTPUT, or INPUT_PULLUP.

digitalWrite(pin, value) - Write a HIGH or a LOW value to a digital pin.

• pin: the Arduino pin number.
• value: HIGH or LOW.

delay(ms) - Pauses the program for the amount of time (in milliseconds)

• ms: the number of milliseconds to pause.

digitalRead(pin) - Reads the value from a specified digital pin, either HIGH or LOW.

• pin: the Arduino pin number.

millis() - To record number of milliseconds passed since the current program began the execution.

This project is to develop a digital stop watch with start/stop and reset option. This system consist of three 7-segment LED unit to display the timing in milliseconds precision. First and second 7-segment LED display seconds value The last 7-segment LED display milliseconds value Use of slide switch to start/stop the counting (HIGH-Start, LOW-Stop) Use push button to reset the counting to initial value (HIGH-Reset) Once it reaches it’s maximum counting, continue again with initial value

Simulated and verified this logic on Arduino Uno using Tinkercad circuits simulator.